Electrical winding.



wemibrm PATENTED. MAR. 5, 1907.

J LATTIG& C L GOODRUM ELECTRICAL WINDING.

APPLICATION FILED MAR 3 1904 RENEWED 1m so 1007 QNITED STATES PATENT OFFICE.

JACOB W. LATTIG, OF WYNCOTE, AND CHARLES LANE GOO DRUM, OF

PHILADELPHIA,

PENNSYLVANIA.

ELEC-TRIGAL. WlNDlNG.

Specification of Letters Patent.

Patented March 5, 1907.

Application filed March 3,1904. Renewed January 30, 1907 Serial No. 354.911.

To LN (whom it may concern.-

Be it known that we, JACOB W. LATTIG and CHARLES LANE GOODRLM, citizens of the provement in Electrical \"\"indings, of which the following is a specification.

Our invention relates to systems and methods of operation involving the use of double-wound coils and other conductors which are closely enough asso iated mechanically and have a sullicient difference of potential between their several parts to make their static capacity noticeable.

llnsuchcase each coil is composed of twin or parallel windings included in opposite sides of a metallic circuit, the coil being neutral for currents in the metallic circuit, but active for currents through the two conductors in parallel. Obviously in the latter case the two sides of the coil would be of the same potential at any given point in the windings and no capacity client would be noticed. With current through the conductors of a metallic circuit, however, the two sides are not at the same potential, and therefore the coil becomes a condenser of low capaiity, and in many cases the ell'octof this, especially where several coils are included, has been to practically SllUI'lL-( ircuit the line, talk in the metallic circuit from cithcr end being better with the other end open than closed. In addition to this cll'cct those coils increase the already undesirable capacity ol' long lines or cables, ahd this with lumped capacity.

The object of our invention is to reduce the capacity of double-wound coils and other pieces of apparatus whorcin the conductors are closely associated and exposed to opposite potentials. Ne attain this object by reversing one conductor or body with rclalion to the other, so that instead ol points between which there is a maximum drop bcing brought together those having the minimum drop will be so associat d. We do not limit ourselves to this specific method or the apparatus for practicing it,'howpvcr. \Yithoul actually reducing the capacity we can noutralizeit in some cases by including other coils possessing self inductance in proper rc lation. i

Our invention is illustrated in the accompanying drawing, whereinl igure 1 is a diagram showing a circuit serving six stations, four of these being grounded. Fig. 2 is a diagram showing the underlying principle involved in oui'method and apparatus. Fig. 3 is a plan view ofa simple form of coil. Fig. 4 shows another method of winding for the long coils.

' phone-stations connected by the metallic ci.rcuit i 2, each being connected thereto through an induction or repeating coil 1. The circuit l 2 is divided into two portions for certain purposes by the insertion of the coil A; but this coil has no effect on the transmission from Y to Y, or vice versa, over the metallic circuit, as its windings are oppositely connected, so that for currents passing through them serially they neutralize each other. For currents passing over the two sides of the metallic circuit in parallel the coil becomes active, however, and presents high impedance to voice-currents or other high-frequency changing-currents. A we have shown a bridged coil 11, and from the middle points oi the windings of these coils, as WLll as from the middle points of the wind ings of coils l, ground taps are taken oil, in which we include the station apparatus indicatcd at X X X X. StationXnow corresponds with station X over a circuit composed of the ground, the taps 3 and 4, and that portion ol' circuit 1 2 lying between coils I and coil A. Stations X and X similarly make use of the circuit composed of the ground, taps5 and b, and that portion of the circuit 1 2 lying to the rightol' coilA. Three distiuctcircuits are hcrc pictured, and the two grounded circuits are absolutely distinct from each other, having, moreover, nothing to do with the capacity cll'cct of coil A, as'l'or thcm conductors 1 and Z are at the same potential always. In corrcspomloncc between stations vY and Y it will be noted that between two points at one end of coil there is a drop of potential, due to, llrst, the resistance oll'cred by one side of coil A; second, the resistance of the extended lino and instruments on the other side of the coil, and, third, the rcsistanccol' the other side of coil. Suppose we take these points at the extremities of the left-hand bridge-(mil i. In any case the drop is obviously due o resistance out and back or double the drop be- Referring to Fig. 1, Y and Y are two tele-' On each side of the coil' tween the ends of the coil A without taking account of the line. With a twin winding on the coileonnected as wound we would have a maximum capacity, for the conductors would be close together throughout their length, and the difi'ercnce of potential between their corresponding points would he at its greatest. Vi e attack both these conditions, but principally the second. The charge which may be c-arriedby such opposed surfaces as those of our conductors varies directly with the potential dillerence and inversely as the square ol the distance between the surfaces. first dispose the conductors so that we inimmize their potential dill'erence, and then we see to arrange them so as-to increase their distance apart without destroying their balanced average ellect on the core.

Fig. 2 showsthe simplest form of coil'enn bodying our invention. Here the wire 1. is carried to theright-hand end of the coil A, then back through the-winding a, and ion ward again, as indicated by the plus-sign. Conductor 2 is led straight to winding a and alter passing therethrough goes on indicated by the minus-sign. Now if two points, such as p p, are taken, one on. each conduetor, it will be observed that if they be con-- neeted only one winding (1/ will be included. .lln other words, between and p there is a drop of potential due only to the coil/1". Similarly, if two points 1) 1') be chosen it will be found that only coil a is included between them, or, in other words, there is a drop of potential due to the resistance of that coil alone and so it will be found if any two corresponding points be selected in the associated windings. Disregarding the outside line resistance, then, we have decreased the potential differences in the coil fifty per cent. and yet, the direction of the turns is undisturbed, the magnetic ell'ects are unchanged. This is important.

Returning now to Fig. l, we have in coil A not only the reversal in connections of one winding, but the windings are subdivided, so as to greatly increase their mutual distances without increasing their distances from the core or their balanced efl ect thereon. Here conouctor 1 passes, as before, to the righthand end of the coil and so back through one set of windings, these being carried on very thin and llat alternate spools a, a &c. doctor 2- is carried forward through similar alternating spools e, (L See. The actual mechanical construction oi the coil is shown in. llig. 3, except that the individual spools are preferably even narrower than those shown. Each conductor is carried through alternatespools all the way round. Bindingposts are carried lor convenience in making connections, wired so that wires load in at one endv and out at the other.

While the form of coil shewn in Fig. 3 is successful. yet in many cases we have pre- Co al ferred to use the simpler form of coil shown in Fig. 2. In that figure only a single layer of each side of the winding is indicated. The method of winding more than a single layer, however, requires separate illustration and is there [ore shown in Fig. 4. it will be observed in Fig. 2 that a connection has to be made from the point p back to the line-wire number 1 at the end of the coil, and of course when more layers are put on this i ondiorend cbnnection would have to he i made from layer to layer. To avoid this, we wind as in Fig. l, and this we claim as a part of our invention. l as before, and the characters 1, 2 3, 4", 5, and 6 to indicate the sue essive layers woundthereon, the arrows indicating the direction ,,oi current therein. N ow suppose the curved arrows N and S to indicate the opposite r0 tary motions of the core in direct and reverse winding. Assume that all windings are started attire left hand and that winding 1 is put on wit-.1 the core revolving; in the direction ol the arrow N Then the winding of 2*'wonld be made with the core revolving as per arrow S, winding 3 "would he made like 2, windings 4. and same direction again as l and winding 6 would he made in the same direction as windings 2 and 3*. In other words, while not "twin wound, the windings are really in pairs I as regards direction, the pairs beingreversed symmetrically with regard to each other, hich makes itpossihle to join coils 1 and 3 at one end, 3 and at the other 4 at the first end, and l and 6 at the other end.- In other words, with this method oi winding eoi'inections can be made from layer to layer without using connecting-wires from end to end, and yet the potential diil'erenee between corresponding points on windings in opposite sides of the coil is kept down to a minimum as stated.

Vi e are fully aware that many other forms of apparatus might be found to carry out our urposes and many variations might be made in the apparatus described herein, but all such variations are within the scope and pur view of our invention and'are contemplated by us. We believe we are the first to attain the desirable results stated in this or any mannor, and our claims are to 'be broadly construed. 1

Having thus described our invention,what we claim is 1.. A coil for transmission systems having two windings and a core, said windings composed of two wires laid on the core so that K their turns for equal current will produce sub- 1 stantially equal n'iagnet c clients, and mei tal h c-- circuit connections for said coil conii prising a pair of mcomnig terminals and a i pair oi outgoing terminals, the incoming ter- 1 urinals being connected to th'e two windings l at opposite endsof the'coil, and. the outgoing Suppose A to be the core,

end, 2 and 5 would be made in the terminals being similarly connected to the other two ends of the said windings, the arrangement being such that for currents in the l two windings and aeoininon core, each winding being subdivided and the subdivision of same general direction from end to end of the core, whereby the potential ditl'erence be tween contiguous points is reduced to the drop around one winding, described.

5. A neutral or differential coil having a low static capacity, comprising a core, an inigether with a pair of incoming and a pair of outgoing cireuit tei'ininals, eaehpair disposed at opposite ends ol the windings, nieutbeing such that lor t'llt'tllt passing scrithe arrangeally through the windings the will ueutral- I izc each other, substantiallv as described.

I}. A coil for electric transmission s vsteiiis employing ditl'erential connections, having two windings upon a core, each winding being subdivided and the subdivisions ol the opposite windings alternated in connection,

substantially as described. i

tial layer of wire wound thereon in one direction, a second and third layer both wound in 5 a reverse direction to the tirst layer, a fourth the two windings alternated on the core, to

and lifth layer both wound in the same direction as the first layer, and so on, the first and third layers being joined at one end of the coil and'the third and fifth atthe other while 40 the second and fourth are joined at one end of the coil andthe fourth and sixth at the other, and so on, substantially as described.

lu test inionv whereof we have hereunto set j our hands, this 19th day of February, A. D. 5 3 1904-, in the presence of two subscribing witnesses.

4. A coil for electric systeins having op- 5 posed windings laid on and connected so that i current. will tlow through tlienrserially in the JACOB- W. LATTIG. CHARLES LANE GOODRUM. Witnesses:

MARY C. MCCARTHY, E. .R. CONNELLY.

substantially. as 30 

